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(No Model.) 4 Sheets-Sheet 1. T. PRESSARD.

STEAM GENERATOR,

No. 432,075. Patented July 15, 1890.

(No Model.) 4 Sheets-Sheet 2.

T. PRESSARD. STEAM GENERATOR.

Patented July 15, 1890.

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T. PRESSARD.

STEAM GENERATOR. No. 432,075. Patented July 15, 1890.

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] UNITED STATES PATENT OFFICE.

THFOPHILE PRESSARD, OF PARIS, FRANCE.

STEAM-GENERATOR.

SPECIFICATION forming part of Letters Patent No. 432,075, dated July 15, 1890.

Application filed May 22, 1889. Sezial No. 311,665. (No model.) Patented in France $eptemher 6, 1888, No. 192,825, and in Bel- 'gium March 6,1889,No..85,298.

and in Belgium, No. 85,298, dated March 6,

1889,) of which the followingis a specification.

The present invention relates to improvements in multitubular steam-generators with removable tubes.

In the accompanying drawings, Figure 1 represents a vertical section of the tubular boiler. Fig. 2 represents a plan of the boiler,

partly in section, 011 the line 111 IV of Fig. 1.

Fig. 3 represents a front elevation of the same, half in section, on line I II of Fig. 1. is a rear elevation. Fig. 5 represents the whole boiler in vertical section. Fig. 6 represents a horizontal section of one of the tubular parts. Figs. 7 and 8 are details of modifications in the manner of joining the bolts and tubes.

The steam-generator consists, essentially, of, first, inclined vaporizing tubes; second, chambers; third, a collector, and, fourth, a reservoir. Two tubes joined to one chamber form a vaporizing element and a verticallysuperposed number of chambers and tubes form a series. The vaporizing-tubes are of two different diameters, the tubes placed at the bottom in the open combustion-chamber and producing a considerably greater quantity of steam than those placed above them being of considerably greater diameter than those arranged above them for the purpose of facilitating the disengaging of the steam and the admission of the water which replaces that transformed into steam. These larger tubes 0 are arranged in pairs, one tube exactly above the other, so that the lower one receives the full action of the fire, and in it formed much more steam than in -the one immediately above, which is almost screened by the lower tube. From this arrangement and the inclined position of the tubes it follows that the steam formed in the lower tube passes direetlyinto the collector B and is at once replaced by water, which descends from the reservoir through the collector B and the upper Fig. 4

tube of the pair or element. It may be said that the lower tube is the vaporizer and the upper one the preliminary water-heater, for the water is heated in the upper tube, but vaporized in the lower one. The arrows at, Fig. 5, indicate the movement of the water, the arrows b that of the steam, and the arrows 0 that of what little steam is generated in the upper tube of each pair. To obtain the same results in the upper tubes F, these latter are arranged quincuncial, Fig. 5, and

although this arrangement distributes the heat more equally to the tubes those situated at the lower part of each element will always be more heated than the upper tubes. This arrangement in quincunx has for result to better cool the gases by obliging them to circulate in zigzag, and consequently to come in contact with all vaporizing-surfaces. The upper tubes may, however, if desired, be arranged vertically above the lower ones instead of the elements being arranged in quincunx.

The elements consisting of the big tubes being those which produce the most steam are also those which produce the most deposit, and for the purpose of keeping these tubes constantly clean the joining chambers D of these tubes are so constructed as to be provided with a chamber for the deposit. This deposit is removed under pressure by means of suitable valves E, Fig. 5. The inclined position of the tubes and difference in the density of the two fluids in the different tubes in consequence of the difference in the temperature produce a circulation of thewater sufficiently rapid to carry with it the deposit produced by the vaporization of the water. When the water and the steam arrive in the collector B, they have to change their direction, and it is at this moment that the deposit can fall to the groundi. e, to the'bottom of the collector B, from whence it isremoved by means of suitable openings V.

The feed-water, which is injected into the rearend of the reservoir A above the level of the water therein, will be cleared of the greatest part of its calcium salts, which it contains in solution, by means 'of high temperature. In this manner it arrives hot and nearly pure in the vaporizing-tubes, where the little deposit which it still contains in. solution is separated by the vaporization, and is drawn into the collector B by the force of the circulating current.

The dome or cupola from which the steam is taken is placed as far as possible from the upper opening of the collector Bt'. 6., from the inlet of the steam into the reservoir A- so that it may entirely free itself of the water which it might take with it. To further insure the steam being dry, at drier II, receiving the steam from the reservoir by means of the tube I, is placed 011 the top of the generator, so that the products of combustion must come in contact with it during their passage to the chimney. From the drier the steam passes to the outlet-valve J.

To obtain the greatest possible utilization I of the fuel, the series of tubes is divided into two by a vertical transverse partition K, the front part being the larger and situated directly above the furnace. A screen L is placed 011 the upper tubes, so that the heat must pass to the front and oblige the gases to pass along the drier II and heat the underv side of the reservoir A. The gases then descend behind the partition K through the second or smaller part to the flue leading to the chimney. The arrows, Fig. 1., show the passage of the gases.

.To render all the tubes quickly removable, I each is provided at its rear endi. c, at the collector end with a forked bolt n, riveted to the tube and passing partly through the collector B, the rear end of the collector serving as the support for the nut of the forked screw-bolt it. At the front end the tubes are provided with bolts having plates m, by means of which they are riveted to the tubes, andwhich pass also through the joining chambers D and G.

To facilitate the mounting of the forked;

bolts on the tubes, plain bolts may be used,

traversed by the rivets, and flat, soas to avoid any reslstance for the water in this narrower part. These bolts are arranged in such a manner that it will be easy to examine the tubes and that the joining chamber G can be provided with autoclave plugs or doors, thus avoiding all possible danger of accidents which exists in other generators where the joints of the plugs are under the influence of the dilatation of the tubes. The tapered ends of the tubes are jointed by power, without any cement, and the dry metallic joint thus obtained is absolutely tight. To remove a tube from the collector or the boxes, it suffices to give a blow with the hammeron the bolt, the

nuts having been previously removed.

The above-described apparatus is fittedwith the usual parts, such as a metallic casing M and the masonry, which serve as the base for the whole apparatus. Doors N in the casing M permit of the examination of the joints of the tubes and the cleaning thereof. The furnace O and the ash-pit P are built collector, of a vertical series of inclined tubes communicating therewith at the upper end, the lower tubes of said series being of large diameter and the upper tubes successively of relatively smaller diameter, whereby the degree of heatimparted to the water contained in the tubes is uniform, substantially as described;

2. In a steam-boiler, the combination, with a collector, of a series of pairs of inclined tubes communicating therewith at the upper ends,

with communications between the tubes of each pair at the lower ends, said pairs of tubes being of larger diameter at the bottom and successively of relatively smaller diameter at the top of the series, substantially as and for the purpose set forth.

3. In a steamboiler, the combination, with a collector, of a series of pairs of inclined tubes communicating therewith at the upper ends, with communications between each pair at the lower ends, the lower tubes of each pair being of larger diameter than the upper tubes of the same pair, and the tubes of the whole series of pairs being of successively larger diameter toward the bottom of the series, substantially as described.

4. In a steam-boiler, the combination, with a collector, of a series of pairs of inclined tubes communicating therewith at the upper ends and a communication between the tubes of each pair at the bottom, the tubes being arranged in quincuncial order, substantially as and for the purpose specified.

5. I11 a steam-boiler, the combination, with the collector and the tubes communicating therewith, of the fastening-bolts having the forked ends riveted to the tubes and the screw-threaded end passing through the collector, substantially as described.

6. In a steam-boiler, the combination, with a collector and a tube or tubes communicating therewith, of bolts for holding the same in position, having one end riveted to the tube- THEOPHILE PRESSARD.

Witnesses:

ACHILLE MARILLIER, R. J. PRESTON. 

